New York, April 22
Scientists have spotted the largest eruption on record from the Sun’s closest neighbor, the star Proxima Centauri.
Proxima Centauri is a small but powerful star. It is just four light years or more than 20 trillion kilometers from our own Sun and is home to at least two planets, one of which may resemble Earth.It’s also a “red dwarf,” the name of a class of stars that are unusually small and faint, explained Meredith MacGregor, an astrophysicist at the University of Colorado at Boulder.
For the new study, published in the Astrophysical Journal Letters, the team observed Proxima Centauri for 40 hours using nine telescopes on the ground and in space.
They discovered that Proxima Centauri had ejected a flare, or burst of radiation that begins near a star’s surface, which ranks among the most violent seen in the galaxy. The flare was about 100 times more powerful than any other similar flare seen from the sun of Earth. Over time, such energy can strip a planet’s atmosphere and even expose life forms to deadly radiation.
“The star went from normal to 14,000 times brighter when viewed in ultraviolet wavelengths within seconds,” MacGregor said.
The team’s findings suggest new physics that could change the way scientists think about stellar eruptions. They also don’t bode well for any spongy organism brave enough to live near the volatile star.
The instruments included the Hubble Space Telescope, the Atacama Large Millimeter Array, and NASA’s Transiting Exoplanet Survey Satellite. Five of them recorded the massive Proxima Centauri rocket, capturing the event as it produced a broad spectrum of radiation.
The technique has delivered one of the most in-depth anatomies of a rocket lit by any star in the galaxy. Although it didn’t produce much visible light, it did generate a huge surge in both ultraviolet and radio rays, or “millimeters,” radiation.
“In the past, we didn’t know stars could blaze in the millimeter range, so this is the first time we’ve looked for millimeter flares,” MacGregor said.
These millimeter signals, MacGregor added, could help researchers gather more information about how stars generate flares. IANS